I actually saw the first one in the theatres, my wife begged me to go. It wasn't bad for what it was, a carbon-copy clone of every 80s man vs. nature disaster movie ever made. Lots of T&A, people doing stupid things, and lots of gore. Jerry O'C. plays a real douche-bag in the movie, and I've had a crush on Elizabeth Shue since Adventures in Babysitting. It moved along well enough, though there was really only one or two major "gore" scenes.
The underwater scene with the two naked girls under the glass boat wasn't too bad in 3D either.